WO2002061971A1 - Systeme de communication a l'aide d'un aerostat captif au-dessus de la surface de la terre et lie a une station de base par une fibre optique - Google Patents

Systeme de communication a l'aide d'un aerostat captif au-dessus de la surface de la terre et lie a une station de base par une fibre optique Download PDF

Info

Publication number
WO2002061971A1
WO2002061971A1 PCT/GB2001/004723 GB0104723W WO02061971A1 WO 2002061971 A1 WO2002061971 A1 WO 2002061971A1 GB 0104723 W GB0104723 W GB 0104723W WO 02061971 A1 WO02061971 A1 WO 02061971A1
Authority
WO
WIPO (PCT)
Prior art keywords
aerostat
communications
base station
antennae
communications system
Prior art date
Application number
PCT/GB2001/004723
Other languages
English (en)
Inventor
Jonathan Francis Adlard
Neil Edward Daly
Carl David Broomfield
Brian Joseph Cahill
Original Assignee
Skylinc Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Skylinc Limited filed Critical Skylinc Limited
Priority to EP01978609A priority Critical patent/EP1358723A1/fr
Publication of WO2002061971A1 publication Critical patent/WO2002061971A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/18502—Airborne stations
    • H04B7/18504—Aircraft used as relay or high altitude atmospheric platform
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/1851—Systems using a satellite or space-based relay
    • H04B7/18513—Transmission in a satellite or space-based system
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/18521—Systems of inter linked satellites, i.e. inter satellite service
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/195—Non-synchronous stations

Definitions

  • This invention relates to a communications system using an aerostat as a platform for backhaul, broadcast or bidirectional wireless antennae. 5 Background to the Invention
  • a limitation in terrestrial communications is that, as higher radio frequencies are used to permit more information to be carried, the propagation characteristics of the radio signals tend more towards direct line-of-sight transmission, requiring, because of scattering and absorption from variations in the landscape topography and the presence
  • Satellite communications systems can cover a large area of the Earth's surface. However, they spread the finite bandwidth available over this much larger area, resulting in a system which offers low performance to many users. They suffer from lack of power and low signal levels due to the great distances over which
  • the present invention provides a communication system comprising a base station connected to a communications network and arranged to provide a radio frequency communications signal to radio transmitting means carried by an aerostat tethered above the base station, characterised in that the radio frequency communications signal is conveyed from the base station to the transmitting means by an optical fibre communications link carried by the tether.
  • the optical fibre communications link may be an optical cable carried by the tether, either as part of the tether or simply supported thereby.
  • the aerostat may carry electrical power-generating means, which could be an engine-driven generator, but which is suitably a wind turbine and/or solar panels.
  • the tether may carry an electrical power cable.
  • Another aspect of the invention provides a cellular communications network, comprising a base station connected thereto, an aerostat provided with a communications link to the base station, and cellular network transmitting and receiving antennae mounted on the aerostat and connected to the base station, and through the base sta- tion to the remainder of the network, via the communications link.
  • a plurality of antennae may be mounted on the aerostat and arranged to transmit signals to different areas on the ground constituting different cells within the network.
  • the antennae may comprise an antenna array, and control means are provided for controlling the signals applied to separate elements of the array such that the resultant radio beam transmitted from the array can be selectively directed towards a chosen location on the ground.
  • the invention also provides a method of controlling a cellular communications network, comprising providing a plurality of cellular network transmitting and receiving antennae on an aerostat positioned above and in communication with a ground base station connected to said network, and controlling the antennae and the communica- tions therewith in such a manner as to create and manage a plurality of different network cells on the ground beneath the aerostat.
  • a mechanism is proposed for operation with a standard point-to-point or point- to-multipoint system, as is known in the art, which allows it to be operated as part of a beamsteered or SDMA system. Both the case of a Time Division (TD) and Frequency Division (FD) system are considered.
  • TD Time Division
  • FD Frequency Division
  • a controller unit is placed after the output block of the standard hub which consists of two elements.
  • the first element is a controller unit which stores details of end users and their location relative to the transmitting antenna (normally present on the aerostat).
  • the bearing of the receiver is also stored locally as antenna weight factors which are used to direct the antenna beams electronically. This information is continuously updated either by using a Direction of Arrival (DOA) algorithm as is known in the art or by directly feeding information about the antenna's orientation; pitch, roll etc to the control unit which updates the weights accordingly to compensate for any changes.
  • DOA Direction of Arrival
  • the second block operates differently according to whether the system is a TD or FD system.
  • TD time slot for transmission and reception of data.
  • the time signal is fed to the controller (described above) and ⁇ ross referenced for each time frame against the location of the user owning that time slot. Using this procedure the beam is steered with time.
  • a FD system assigns a small portion of the total spectrum to each user.
  • the signal needs to be filtered so that each individual user is isolated into a separate circuit.
  • the controller unit described above then correlates each users location information and transforms each channel accordingly using the weights described above. Once weights have been applied for each user the separate channels are combined and transmitted to each user.
  • Yet another aspect of the invention provides a communications system comprising a communications satellite in earth orbit, and a plurality of earth stations for transmitting communications signals to and receiving signals from the satellite whereby any of the earth stations may transmit communications signals to any of the other sta- tions, wherein at least one of the earth stations comprises a base station in communication with an aerostat maintained at a predetermined location relative to the base station, the aerostat carrying at least one antenna for transmitting signals to and receiving signals from the satellite and being maintained at an altitude above the earth's surface such that radio signal attenuation between the satellite and the aerostat is substantially smaller than that between the satellite and the ground at the same location.
  • the height of the aerostat above the earth's surface will be selected such that the signal attenuation between the satellite and the aerostat is substantially smaller than that between the satellite and the ground at the same location.
  • the aerostat may be maintained at an altitude of up to 8km above the surface.
  • the system of the invention permits provision of broadband communications and other global services, and could offer hybrid network solutions.
  • a network could start as a pure platform network, then integrate (acting independently, or integrated) terrestrial, fibre infrastructure and other networks with time.
  • the system has the ability to offer dedicated high data rate bi-directional signals to a point(s).
  • the aerial platform could also act as a backbone network to existing communications such as a mobile network backbone. This could happen independently or integrated into the platform other communication requirements.
  • the system of the invention could offer backbone and other services to current networks, or dedicated high data rate links, for example links to a business park could then potentially be broken down to allow access by multiple parties (via wireless or cabled access).
  • a geo-stationary network of satellites orbiting the earth may be provided, which communicate with aerial platforms and then to other networks.
  • the satellite network would require three or more orbiting geo-stationary satellites. This would provide the satellite section of a hybrid network.
  • the links between the satellite and other net- works i.e. the aerial platform, can use time division multiple access, to allow aerial platforms in close proximity, the opportunity to access the channel without disruption caused by interference etc.
  • the network can also employ Space Division Multiple Access (SDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiplexing (OFDM), Code Division Multiple Access (CDMA), DAMA and CF-DAMA.
  • SDMA Space Division Multiple Access
  • FDMA Frequency Division Multiple Access
  • OFDM Orthogonal Frequency Division Multiplexing
  • CDMA Code Division Multiple Access
  • DAMA DAMA
  • CF-DAMA CF-DAMA.
  • coding techniques which could be one or more of the following coding techniques, space-time codes, turbo codes, multi-level coded modulation, concatenated codes and block codes.
  • the necessary payload to provide the satellite network can be launched on an independent satellite or can be fitted to existing satellites.
  • the satellite-to-platform transceivers for the platform can be mounted on the shell of the aerostat, typically the upper section or roof, within the body of the aerostat (inside gas filled shell) and/or on the payload mounting.
  • Smart antennae, mounted as previously stated but typically on upper section, may also be used for transmitting radio signals to satellite.
  • Optical trans- ceiver equipment mounted to a platform would also require pointing accuracy controls to propagate radio signal in the correct direct of other network such as other platforms and satellite networks. Points of reference are required for the adaptive platform-to- satellite pointing accuracy method. This would typically require the specific location of the satellite, sup-platform point and the location of the aerostat (typically determined using GPS or by ground reference signal and processing). Optical signals transmitted to the platform would thus be directed such as to compensate for platform movement and or stability.
  • the platform can be used for propagation planning purposes for a multiplicity of communications based services (i.e. 2G/3G and BFWA) and other radio requirements.
  • the platform can be provided with a transceiver that communicates with another transceiver (fixed or mobile) on the ground to provide measurement data which can be in- terpreted into useful results. These results can help to define radio channel characteristics for various standards of radio requirements.
  • the platform deployment and measurement facility which could be mobile in nature (i.e. fitted to a vehicle), can be deployed at the appropriate location and potentially carry the necessary test and communications equipment. Processing of such data could be done locally, or transmit- ted/transported to an appropriate location. Backhaul communications for such a test facility could be via other networks, with the appropriate interface mounted to the ground/mobile unit.
  • Such a facility can be manned or un-manned, tethered or un-tethered and may be remote pointed or programmed in advance of its measurement locations/route.
  • the platform could travel independently and transmit data to a remote (fixed or mo- bile) facility.
  • the data could be fed via a tether to a ground unit, stored and processed later or transmitted via an existing network to a processing facility.
  • Typical channel effects and measurements may be propagation effects, losses at varying frequencies, fading, multi-path measurements, Doppler and other.
  • Such ele- ments typically vary with physical/ geographical location, the plane of propagation (i.e. horizontal, slant or vertical plane) height, temperature, rain, air density, water vapour content, and the presence of other signals and interference.
  • the radio channel characteristics and propagation effects By using single or bidirectional links at a required frequency, we can evaluate the radio channel characteristics and propagation effects. Imaging used to predict line-of-sight propagation is particularly beneficial at high frequencies. The imaging could be done by using photography, video, and other types of spectral imaging (i.e. thermal is an example of spectral imaging).
  • the platform measurements and particularly the imaging can be use to produce 3-Dimensional models of the ground terrain, clutter, and the physical environment.
  • 3D models are used for a multiplicity of services such as propagation planning tools (such as PlanetTM), 3D imaging of buildings, web pages, producing virtual reality maps and models, mapping and modelling forms within the physical environment, aerial photography, video, laser radar, triangular mapping techniques and the appropriate software could be required for producing 3D profiles from imaging data.
  • propagation planning tools such as PlanetTM
  • 3D imaging of buildings, web pages producing virtual reality maps and models, mapping and modelling forms within the physical environment
  • aerial photography, video, laser radar, triangular mapping techniques and the appropriate software could be required for producing 3D profiles from imaging data.
  • These models can then by applied to a multiplicity of requirements but are particularly applicable to propagation planning and the associated propagation planning tools.
  • SNGs satellite newsgathering services
  • This technology requires expensive mobile vehicles, multiple persons to operate equipment, and incurs running costs due to erecting equipment and for leasing satellite capacity.
  • Use of the aerostat platform of the invention to relay data/pictures from a remote location back to a required point could substantially reduce costs.
  • transceivers capable of operating in the BFWA frequency band, which could be fitted directly onto or separate to camera/unit housing.
  • the requirement for current SNGs for areas could be removed within a platform coverage region.
  • simple trans- mitters could be used. These maybe built directly into the camera for example or installed into PCs/laptops for relaying data/images.
  • the news gathering services could exploit aerial platforms to provide such data services or deploy a tailored aerial platform for their own purposes, thus producing a local area network. This approach would also be suitable for use with sporting and other large public events.
  • the system of the invention may be used to provide image processing services, such as surveillance, traffic monitoring, filming and photography, early warning systems (i.e. fire and flood detection), in-premises monitoring (sensors, video and communica- tion), home care for the elderly, and security.
  • image processing services such as surveillance, traffic monitoring, filming and photography, early warning systems (i.e. fire and flood detection), in-premises monitoring (sensors, video and communica- tion), home care for the elderly, and security.
  • Another aspect of the invention provides for the use of the system for propagation planning.
  • a key time-consuming and costly element associated with the roll-out and planning of any radio based system is the need to plan the location of the transmitters accurately to optimise performance.
  • software tools can be used to aid this process, it is still necessary to make measurements to establish whether a given site meets the requirements of the system.
  • a tethered aerostat makes an ideal tool for this job as it can be easily moved to the location of the test, inflated and flown to the required altitude with a suitable transmitting/ receiving test payload. Operatives may then proceed to make mobile measurements in the locality so as to establish the suitability of the site.
  • FIG 1 shows a communications network in accordance with the invention
  • Figure 2 shows an aerostat and its base station
  • Figure 3 illustrates the means for handing off between fixed antennae in the system of Figure 2;
  • Figure 4 shows the downlink part of the system
  • Figure 5 shows the uplink part of the system
  • Figure 6 shows an alternative arrangement of the downlink system
  • Figure 7 shows an alternative arrangement of the uplink system
  • Figure 8 shows yet another alternative arrangement of the downlink system
  • Figure 9 shows the uplink system corresponding to the downlink system shown in Figure 8.
  • Figure 1 illustrates the scope of the network containing the tethered aerostat platform 1 and shows the interconnectivity of the unit to other services.
  • Terrestrial wireless techniques 2 including G, 3G, 4G, LMDS and MMDS, operate within the confines of their respective propagation characteristics and bandwidth
  • optical cables, waveguides and coaxial cables 3 provide services to areas where the last-mile cost can be recovered and terrestrial telephone lines 4 offer analogue, ISDN and xDSL services to the majority of the population according to their location.
  • communication may occur via the radio or optical spectrum to neighbouring platforms creating fast inter-city data links.
  • the aerostat 1 provides an elevated platform which gives an extremely large field of view to its onboard antenna systems, extending the potential range of communications services and enhancing the ground area over which line of site (LOS) paths can be achieved.
  • the aerostat 1 is constructed from a high strength gas retaining fabric which is inflated with a lighter-than-air gas which is suitably Helium or Hydrogen, although other gases may be used.
  • the aerostat is tethered to the ground via a single or multiple tether 20.
  • the role of the tether is to fix the location of the aerostat in space above the Earth's surface and to reduce its ability to pitch and roll.
  • the tether 20 consists of one or more lines designed to stabilise the craft. They can be constructed from steel or modern fibres such as Kevlar, Zylon or Spectra as is known in the art. Attached to the tether, or incorporated into its structure, are a data link 21 , described hereinafter, and a power link 22 to power the craft or recover energy in cases where a renewable source running on the aerostat is running at over-capacity. Supplying power to the aerostat and communications payload is potentially a problem. A liquid or gas driven electrical generator or a battery or 240v mains supply can be used on the ground.
  • the aerostat and payload could be powered from the ground through a set of electrical cables running up the tether. If the wrong system is used the efficiency of the tether cable supply could be very low and a great deal of electrical heating could take place along the tether electrical supply cables.
  • Several alternative systems may be employed for reducing this loss and increasing power transfer efficiency.
  • the first solution is to have a small alternating current substation on the ground that transforms up the main supply to approaching, if not exceeding, 1000 volts a.c. (this could be several thousand volts).
  • the transferred power would then be down-converted on the aerostat to provide a.c. power to motors and regulated d.c. power for the communications payload.
  • This high voltage transfer solution means that only low current needs to flow in the tether power cables and hence the l 2 R cable heating is reduced and efficiency increased. This is how electrical power is transferred throughout a typical mains national grid.
  • a second solution is to simply transfer the power at mains voltage level and frequency, as this allows a simple ground system. The voltage would then be down- converted on the aerostat and regulated for those systems that require a clean d.c. input. This system would be less efficient than the first proposed solution but less complex and costly.
  • a third system is to increase either or both the power supply voltage and frequency.
  • the up-converting and down-converting trans- formers used become smaller in size and cheaper in cost. If solid state up and down conversion is used, with a switched capacitor converter type, then capacitor size, weight and cost can all be reduced.
  • the supply switching frequency increases, the skin effect in the tether supply cables becomes more of a problem and current densities will be increased. Therefore l 2 R heating becomes larger and efficiency is again reduced. This can be counteracted some way by not using very high switching frequencies and using multistrand cable instead of a solid core cable, as this increases the effective cable surface area and hence reduces current density. A good oxygen free copper cable will have lower resistivity and hence reduced loss.
  • Silver cable could be considered, as its conductivity is 17% higher than copper or silver plated cable.
  • altitudes of up to approximately 8 km are achievable using tether technology, although higher altitudes are potentially possible in the future.
  • the presence of the tether allows the provision of power, and data directly from the ground overcoming the two major problems associated with the use of non-tethered or free flying craft for the purpose of wireless communications.
  • the tether system also allows the location of most of the processing systems and communication systems to be on the ground rather than on the craft allowing them to be housed in a safe environment and maintained while the aerostat is still in flight without loss of service. This results in the aerostat being a 'bent pipe' system with a simple antenna payload 300 in the air and minimum support equipment.
  • the antenna subsystem 23 sends signals to the ground based subscriber unit
  • CPE CPE
  • the role of the antenna(s) is to provide an effective means of relaying the data to multiple users, stationary or mobile, on the ground.
  • a single antenna or multiple anten- nae each with a single or many independent data feeds may be used, creating a fixed or dynamic pattern on the Earth's surface.
  • a frequency reuse pattern may be used whereby neighbouring antennae broadcast and receive different frequency bands.
  • polarisation for example linear, co-polar, cross-polar, circular or elliptical polarisation or any combination of these may be used to maximise the throughput of the system.
  • the antenna subsystem 23 may consist of antennae creating cellular patterns, or concentric rings on the Earth's surface or may roam across the Earth's surface or may create an umbrella cell covering a large area or may have each of the above present
  • Antennae used for the purpose of sending and receiving signals may form a sin- gle transmit/ receive unit or may split the transmit and receive roles into separate units to reduce signal interference or complexity and cost.
  • Antennae may be of any conventional type including: rectangular or cylindrical horns; rectangular or cylindrical single or dual ridged horns; lensed horns of any of the above types; scalar horns; fractal antennae; z-transform antennae; logarithmic antennae; monopole or dipole antennae; patch antennae of any geometry; dish antennae including cassegrain; offset feed antennae or elliptically shaped antennae; spiral or helical antennae or reflector/collector designs.
  • Another possible antenna type is the quad ridged horn.
  • Delivery of the signals to the ground based user irrespective of movement of the aerostat platform may be achieved by a number of means including hand-off, gim- baling of the entire antenna system, deployment of beam steering antennae or by the use of smart antennae or of mechanically adaptive antennae.
  • Gimbaling employs a system isolating the antenna array from the body of the aerostat. This unit can be mechanically moved so as to compensate for motion of the aerostat.
  • This unit can be mechanically moved so as to compensate for motion of the aerostat.
  • Hand-off assumes a system where the antenna beam pattern may move across the Earth's surface or the subscriber may move such that he moves out of the operating area of one beam and into the scope of another. A further hand-off scenario may be applicable when the user moves out of the range of the platform but this is not considered here.
  • Hand-off techniques are known in the art and will not be elaborated here. However a novel system is suggested which allows the deployment of standard hub equipment which may have no inherent hand-off capability. This system is shown in Figure 3 and is described hereinafter.
  • Tracking antennae which may or may not be electronically controlled smart antennae, or mechanically steerable or adaptive reflector designs can be employed to elec- tronically redirect the beam to the mobile or stationary ground based user independent of the motion of the aerostat and/ or the subscriber.
  • the orientation of the aerostat is used to control the direction of the antenna's beam effectively compensating for motion of the craft.
  • a feedback circuit is employed which can take data from the control systems de- scribed in this document and feed them to the control unit of the antenna.
  • the antenna beam can be held stationary on the ground or may track a mobile user.
  • a far higher degree of control can be achieved as the system detects the direction of arrival (DOA) of the subscriber unit and stores this information.
  • DOA direction of arrival
  • the Smart antenna uses the DOA information to redirect the data to the subscriber.
  • An alternative system may involve the platform registering the initial state of us- ers and detecting which cell they are located in. As the platform then moves, the tacking antennae apply a target hold algorithm to maintain the communications channel.
  • Wide area umbrella antennae can be used to illuminate a large area of the Earth's surface below the airship affording a means of providing communication irrespective of motion of the craft. They are useful for backing up the services provided by the highly directional and tracking antennae.
  • Shaped reflector, patch or shaped lens antennae are particularly suitable for this application as they provide a means of creating an extremely wide beam profile.
  • Other antenna designs are also usable.
  • the control system 24 enables the aerostat to operate in harsh weather condi- tions beyond those of a conventional aerostat. Such systems have not been essential in the past as generic aerostat applications do not require high stability of the craft to the extent required for communications purposes.
  • the system may include:
  • powered control systems such as motors and ion engines to adjust the location and orientation of the craft and to counter external environmental effects in- eluding turbulence and wind gusts;
  • Power augmented controls for motors may permit stabilisation or positioning of the platform and alleviate the effects of downdrafts and kiting.
  • the tether may employ damping mechanisms to control undesired movements, weak links to release portions of the tether selectively in extreme conditions, and torque control winches to assist in position stabilisation.
  • Sensors may be employed on the aerostat or elsewhere to detect adverse weather such as high winds, thunder storms, changes in pressures, lightning, as well as conditions such as parted tether, kiting, tether stress and damage, and helium leakage. They may also warn of approaching aviation.
  • the information provided by the sensors may be employed in intelligent processing in a processor on board and/or located on the ground utility and/or from a remote location and fed via link options.
  • the full duplex high data rate service made possible by the network topology described above is over-specified for the home user, the SoHo (Small Office Home Office) user or residential users, as in these cases the data rate in the direction of the user normally exceeds that required from the user.
  • an asymmetric system can be deployed whereby the user still receives signals from the aerostat to a CPE as described above.
  • data is not transmitted to the aerostat; rather it is channelled via conventional means such as via a telephone with a modem or using a conventional ISDN channel.
  • radio is used for sending data from the user to the aerostat, but at a lower data rate than that from the aerostat to the user.
  • a high precision steerable antenna can be used to augment the performance of the standard antenna pattern under exceptional circumstances.
  • This steerable antenna can be operated electronically i.e. a Smart antenna, or may be mechanically steered or may be an adaptive reflector antenna as known in the art.
  • this antenna is to provide backup to the normal antenna systems in cases where the radio link may be broken by for examples adverse weather / rain events or by extreme short term coverage requirements in a particular area, for example at a football match or some such gathering of people.
  • the adaptive spot tracking antenna will allow for the location and the beam width of the beam to be controlled so as to perform its roll.
  • An airborne refuelling system 25 or parts thereof may also be located on the aerostat and help to increase the aerostat flight time and reliability.
  • Lighter-than-air vehicles have a limited flight time which is caused by the continuous loss of the lighter- than-air gas through the craft's fuselage.
  • the gas is often helium or hydrogen, which are extremely small molecules, loss is inevitable, as no material can be made through which these particles are unable to diffuse. For most aerostats this is not a significant problem and they can be returned to the ground, their on-board gas supply replenished and once again they may be re-launched.
  • One aspect of the invention proposes the use of a second craft, probably smaller than the craft receiving the gas.
  • This may be a small aerostat, but may be any aircraft.
  • the refuelling craft as it shall be know is flown to the altitude and location of the aerostat with the aid of cameras and other suitable proximity sensors.
  • the refuelling craft may be guided up the tether to the service craft
  • a flexible hose can be guided so as to mate with the valve on the service craft, and lighter-than-air gas can then be pumped so as to replenish the gas to the required level.
  • the gas may be stored as pressurised gas, or in liquid or solid form when possible or in the case of the refuelling craft being a UAV it could refill the service craft from its envelope.
  • Elements 26 serving the purpose of system failure handling or fail-safe systems may also be included.
  • a commercial switching hub connects the aerostat system to the rest of the world via the dynamic router if necessary.
  • a universal adaptor 28 is included at this point which allows for the signal to be sent received directly using a waveguiding structure such as an optical fibre or a hollow waveguide or a coaxial transmission system. Provision is also made for the use of a terrestrial point-to-point microwave link as is known in the art or by means of a satellite link via an external antenna.
  • the base station may include a cache, whereby network traffic such as web pages, audio files etc can be stored on a storage medium, e.g. a hard disk, at the loca- tion of the network gateway.
  • a storage medium e.g. a hard disk
  • the system may be powered by means of a cabled mains supply 29 which will preferably run underground immediately beneath the aerostat to prevent major disrup- tion in the case of a failed tether.
  • a local generator or storage battery is also possible.
  • the system provides a means of handing off between fixed antennae, located on the aerostat, whose antenna patterns move over the Earth's surface as result of variation in location and orientation of the aerostat For the tethered solution location is not a major problem as the aerostat's station can be kept down to as little as 10 m or so at an altitude of 1 km.
  • the system comprises units 31, a dy- namic router or switch which receives continuously updated information on the current location and orientation of the aerostat via unit 33.
  • the routing switch performs the task of keeping a look up table of which ground based user is associated with which fixed antenna on the aerostat and hence which hub signals need to be directed to in order to complete the circuit between the user and the rest of the world.
  • the units 32 are commercially available wireless hubs. Without the use of the dynamic routing element it would not be possible to perform signal hand off for a generic hub. It is envisaged that under certain circumstances the roles of units 31 and 32 may be combined to give a combined dynamic routing hub which can provide system hand-off features.
  • Figure 4 illustrates one form of the downlink part of the system of the invention.
  • the system comprises a base station 41 which includes, if necessary, a base station to system interconnector/ adapter, allowing the BFWA base station to mate with the proposed BFWA communications link.
  • the adapter consists of a waveguide to K, 2.4mm or V connector adapter such as the commercially available Flann Microwave 22094- KF20.
  • An attenuator 42 may be required to convert the high output power of the BFWA base station 41 to an acceptable level for the optical transmitter 44.
  • This device could sit before or after the base station adapter and be produced in waveguide or have K, 2.4mm or V connectors or any other type of microwave/mm-wave connectors that operate up to and/or above 40GHz.
  • Such a commercially available device is: Flann 22580 (fixed) or 22113 (variable)
  • a stabilised DC power supply/bias 43 (required if an external optical modulator with no internal DC bias circuitry) is used in order to set the modulation depth and hence determine how linear the RF modulation on to the optical carrier is.
  • An RF bias tee is required to allow superposition of the DC and AC signals on to the same microwave input such a device is the 8810EF from Inmet Corporation.
  • the optical transmitter 44 allows the modulation of, in the case of BFWA, a data modulated 28GHz or 40GHz carrier on to an optical carrier. In the case of UMTS or MMDS, this data carrier will be considerably lower in frequency.
  • the optical carrier could be any feasible optical frequency, with the current standard communication wavelengths being between 800nm and 1600nm.
  • This device could take the form of a directly modulated laser diode, with an integrated electro-absorptive modulator such as the Mitsubishi ML9XX14, although current state of the art technology offers an upper modulation frequency limit of around 10GHz.
  • An alternative and preferred optical generation scheme is a lower cost laser diode such as the Mitsubishi ML60116R and an external optical modulator such as a Lithium Niobate Mach-Zender type like that of the IOAP-MOD 9203 from SDL or an electro-absorptive modulator or a single packaged laser diode, drive circuitry and modulator like that of Marconi's 40Gbps optical transmitter.
  • the power supply unit is a dedicated unit required to drive the laser diode, if an external laser diode is used.
  • Fibre optical cable 45 is required for the RF modulated optical carrier transmission to the receiver.
  • the cable runs up the aerostat's tether and may be armoured, or not armoured if weight is a problem or the environment is not too harsh. If a steel armoured fibre optic cable is used, then the cable could also be used as the aerostat's tether, as the fibre will stretch more than the steel before breaking. Such a cable is produced by Pinacl Communication Systems. If an armoured fibre optic cable is used, then several fibres can be run up an individual armoured sheath and therefore several com- munications payloads can be fed with a data modulated RF signals. Either monomode cable or multi-mode cable can be used dependant on the characteristics of the system and attenuation and dispersion requirements, which will be distance dependant
  • the optical receiver 46 is required for reception of the RF modulated optical carrier. Demodulation of the optical carrier is also performed within the receiver, i.e. the signal output from the receiver should be the same data modulated RF carrier that was injected into the optical transmitter.
  • the optical receiver 46 could consist of a high speed photodiode again operating at optical wavelength around the standards used at this current time (800nm-1600nm) and or considerably lower and/or higher in frequency.
  • the photo diode could have a low RF bandwidth of around 3GHz for MMDS and UNTS applications but will require a much faster switching RF bandwidth of in excess of 40GHz for BFWA applications.
  • LNA low noise microwave
  • Such a photodiode is that of the DSC1 OS by Chipsat and an appropri- ate LNA would be a QLN series amplifier by Quinstar.
  • An alternative is a state of the art optical receiver such as Marconi's 42.5Gbps optical receiver, which consists of a single package incorporation a high-speed photodiode, LNA and appropriate biasing circuitry.
  • a power amplifier 47 is required to amplify the low output RF signal from the optical receiver 46 to an acceptable level to drive the antenna 49 for free space propa- gation. If efficiency is not a problem then this amplifier should be run in it linear operating region as to reduce the level of distortion introduced by the amplifier to the data carrying RF signal. Alternatively the amplifier can be operated closer to saturation and a predistortion module fitted before this amplifier to linearise the amplifiers input-output characteristics. Alternatively an amplifier linearisation technique such as a feedforward amplifier could be employed. The gain and maximum output power of this amplifier will be determined by the gain of the transmit and receive antennae, the modulation scheme used the propagation distance the weather conditions the RF frequency used the maximum legal radiated transmit power and the RF input level.
  • Automatic gain control may be required on this amplifier to increase/ reduce the radiated RF power in bad/good weather conditions and/or free space path length changes and/or variations in receive antenna gain.
  • An appropriate amplifier for a 28GHz BFWA system may well be something like the Quinstar QLN series
  • a bandpass filter 48 is required primarily to produce good isolation between transmitted signals and received signals. That is, the transmit antenna will not propagate with any serious power level any signal out side of the transmit band whether they are produced from distortion in previous components or intermodulation/mixing effects. This means that the receiver's front end cannot get saturated by any spurious transmitted signal from the transmit section.
  • Such a filter could be manufactured from waveguide or be printed onto a microwave substrate in such a form as microstrip, stripline, triplate or coplanar waveguide.
  • the input and output to the filter could be waveguide and/or a coaxial microwave connector such as a K connector or V connector or 2.4 mm connector.
  • the transmit bandpass filter and receive bandpass filter could be replaced by a high isolation diplexer and a single transmit/ receive antenna used.
  • the antenna 49 is required to allow free space propagation of the data-carrying RF signal.
  • the antenna will also allow gain and directivity to be added to the system this will allow only selected geographical areas to be illuminated with/ receive with adequate power of the data modulated RF signal.
  • the types of antenna that can be used for most types of system, that is 2G, 3G (UMTS), MMDS, BFWA, LMDS propagation is either array antennae or single antennae.
  • Antennae used could be monopoles, dipoles, printed and/or not printed patches, printed and or not printed helixes, conical antennae, spirals (planar and/or conical), horn antennae (ridged and/or not ridged and/or lens type), dish antennae (front fed and/or rear fed), and slot antennae (waveguide and/or printed), for example.
  • An array antenna could be an array of any size and dimensions of any of the above single antennae.
  • the uplink system shown in Figure 5 comprises an antenna 51 , which may be the same antenna as in the downlink system or a separate antenna. It is required to re- ceive the free space propagated data carrying RF signal and transform it to a waveguide propagation or coaxial cable propagation RF signal.
  • the antenna will also allow gain and directivity to be added to the system to allow only signals from selected areas illuminated on the ground to be processed.
  • the types of antenna will be the same as for the downlink antenna.
  • a bandpass filter 52 is required primarily to produce good isolation between transmitted signals and received signals. That is any signals received by the antenna that are higher or lower in frequency than the allotted receive bandwidth will experience high attenuation and will not saturate the receivers front end (the LNA). The insertion loss of this filter in the pass band should be as low as possible to increase the sensitivity of the receive system.
  • a low noise amplifier 53 is required to for several reasons. Firstly the amplifier is required to boost the received signal power level up to an optimum drive level for the optical transmitter (a second stage medium power amplifier may also be required). The second reason for using a low noise amplifier is to increase the sensitivity of the system, that is allow smaller signal levels to be received and still allow the system to function as designed.
  • the input and output to this amplifier could be waveguide and/or coaxial microwave connectors such as K connectors, V connectors or 2.4 mm connectors.
  • Such a low noise amplifier is the QLN from Quinstar.
  • a medium power amplifier 54 may or may not be required. If the signal ampli- tude received by the receive antenna is very low and the RF power required to drive the optical transmitter is comparatively high then a second stage amplifier will be required firstly to make up the additional gain required to boost the received RF signal an acceptable level for the optical transmitter, and secondly to allow a more commercially available lower gain, lower power low noise amplifier to be used. This amplifier's gain will be dependant on the LNA gain, the receive antenna gain, the received power level and the optimum drive level for the optical transmitter.
  • the RF input and output connectors could be waveguide, K, V, SMA, 2.4mm or any other standard and/or non- standard microwave/mm-wave connector.
  • a stabilised DC power supply/bias 55 (required if an external optical modulator with no internal DC bias circuitry) is used in order to set the modulation depth and hence determine how linear the RF modulation on to the optical carrier is.
  • An RF bias tee is required to allow superposition of the DC and AC signals on to the same microwave input such a device is the 881 OEF from Inmet Corporation.
  • the optical transmitter 56 allows the modulation of in the case of BFWA a data modulated 28GHz or 40GHz carrier on to an optical carrier. In the case of UMTS or MMDS this data carrier will be considerably lower in frequency.
  • the optical carrier could be any feasible optical frequency, with the current standard communication wavelengths being between 800nm and 1600nm.
  • the transmitter 56 may be essentially of the same type as in the downlink system described with reference to Figure 4.
  • the power supply unit is a dedicated unit required to drive the laser diode if an external laser diode is used.
  • the fibre optical cable 45 has been described with reference to Figure 4, while the optical receiver 58 is essentially the same as the receiver 46.
  • Figures 6 and 7 illustrate an alternative arrangement of downlink and uplink sys- tems.
  • the main difference between this system and the first proposed system is the fact that unmodulated baseband data is sent down the optical fibre and not a data modulated radio frequency modulated on to an optical carrier.
  • the baseband data sent down the optical fibre is modulated at the top end (in the aerostat payload) to whatever specification is required, whether it be BPSK, QPSK, 16QAM, 64QAM or any other digital modulation scheme and on to what ever carrier frequency required for either BFWA, MMDS, LMDS, 2G or 3G standard.
  • a microwave/mm-wave synthesised signal generator 61 a signal modulator 62 of whatever type is required for the standard to be used (BPSK, QPSK, 16QAM, 64QAM, etc..) and operating at what ever carrier frequency is required for the frequency standard (BFWA, MMDS, LMDS, 2G, 3G, etc..) and some possible filtering will all be required.
  • This system takes some of the tight requirements from the optical transmitter and receiver, as they are no longer required to run at the RF frequencies but at the data rate. For example a BFWA system would have previously required an optical modulator that could switch at 28GHz or 40GHz and now only requires a switching speed of a few hundred MHz.
  • This system now has the provision to send the data for several channels down the same fibre and use the same transmit/ receive modules but modulate on to different carrier frequencies at the aerostat platform end.
  • the base station side of the system will require a demodulator to remove the data from the base station carrier, whether, it is BFWA, MMDS, . UMTS, LMDS or any other broadband standard.
  • An optical carrier can then be directly modulated with the baseband data.
  • the additional components required over the components of the original proposed system are a demodulator 63, a microwave/mm-wave synthesised signal generator 64 and a bandpass or low pass filter 65 to remove any out of band.
  • the uplink system shown in Figure 7 is essentially the same as in the downlink system shown in Figure 6, but reversed. The only major differences are that the modulator and demodulator exchange positions in the system, as do the optical transmitter and receiver.
  • FIGS 6 and 7 can be simplified by removing the demodulator and signal generator from the base station in the downlink system and supplying the optical transmitter with base-band data straight from the base station, with a corresponding simplification of the base station in the uplink system.
  • Figures 8 and 9 which are diagrammatically similar to Figures 6 and 7 and in which like reference numerals identify components which are the same as in Figures 6 and 7, the downlink system involves the use of a down-converted data modulated radio frequency signal modulated on to an optical carrier and sent down the optical fibre.
  • the radio on fibre signal sent down the optical fibre can be up-converted at the top end (in the aerostat payload) to whatever carrier frequency is required, for example BFWA, MMDS, LMDS, 2G or 3G standard, or it can simply be up-converted to the original carrier frequency before down-conversion.
  • carrier frequency for example BFWA, MMDS, LMDS, 2G or 3G standard
  • additional hardware will be required on the aerostat.
  • a microwave/mm-wave synthesised signal generator and an up-converting mixer 83 and a down-converting 82 mixer will be required operating at what ever carrier frequency is required for the frequency standard (BFWA, MMDS, LMDS, 2G, 3G, etc.). Some possible filtering may also be required.
  • This system takes some of the tight requirements from the optical transmitter and receiver, as they are no longer required to run at the previously high RF frequencies but at lower intermediate frequencies. For example a BFWA system would have previously required an optical modulator that could switch at 28GHz or 40GHz and now could require a switching speed as low as a few hundred MHz. This system now has the provision to send several different intermediate frequencies for several different channels down the same fibre and use the same transmit/receive modules but up-convert to the same or different carrier frequencies at the aerostat platform end.
  • the base station side of the system will require a down-converting mixer and RF synthesiser to produce a lower intermediate frequency (IF) than the base station carrier frequency, whether it is BFWA, MMDS, UMTS, LMDS or any other broadband standard.
  • An optical carrier can then be directly modulated with the IF.
  • the additional components required over the components of the original proposed system are several mixers, a microwave/mm-wave synthesised signal generator and several bandpass or low pass filters to remove any problematic out of band signals.
  • the disadvantage of this system is its increased complexity.
  • the uplink system is very much the same as the downlink but in reverse. The only major differences are that the down-converting mixer 82 and up-converting mixer 83 exchange positions in the system, as do the optical transmitter and optical receiver.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Astronomy & Astrophysics (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne un système de communication qui comprend une station de base (27) connectée à un réseau de communication et prévue pour fournir un signal de communication radioélectrique à un émetteur radio (23) supporté par un aérostat (1) captif au-dessus de la station de base. Le signal de communication radioélectrique est véhiculé de la station de base au moyen de transmission par une liaison de communication (21) à fibres optiques supportée par le câble d'ancrage (20)
PCT/GB2001/004723 2001-02-01 2001-10-25 Systeme de communication a l'aide d'un aerostat captif au-dessus de la surface de la terre et lie a une station de base par une fibre optique WO2002061971A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP01978609A EP1358723A1 (fr) 2001-02-01 2001-10-25 Systeme de communication a l'aide d'un aerostat captif au-dessus de la surface de la terre et lie a une station de base par une fibre optique

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0102639.2 2001-02-01
GBGB0102639.2A GB0102639D0 (en) 2001-02-01 2001-02-01 Broadband communications system

Publications (1)

Publication Number Publication Date
WO2002061971A1 true WO2002061971A1 (fr) 2002-08-08

Family

ID=9907990

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2001/004723 WO2002061971A1 (fr) 2001-02-01 2001-10-25 Systeme de communication a l'aide d'un aerostat captif au-dessus de la surface de la terre et lie a une station de base par une fibre optique

Country Status (3)

Country Link
EP (1) EP1358723A1 (fr)
GB (1) GB0102639D0 (fr)
WO (1) WO2002061971A1 (fr)

Cited By (129)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2886491A1 (fr) * 2005-05-31 2006-12-01 Thales Sa Dispositif de transmission de signaux captes
RU2492574C2 (ru) * 2011-02-15 2013-09-10 Открытое акционерное общество Омское производственное объединение "Радиозавод им. А.С. Попова" (РЕЛЕРО) Способ установки ретранслятора при организации радиолинии связи
EP3035071A3 (fr) * 2014-11-30 2016-10-19 Saab Medav Technologies GmbH Transmission de signal et dispositif de retenue pour des antennes embarquées d'un système de localisation rf
WO2017017100A1 (fr) * 2015-07-27 2017-02-02 Avanti Communications Group Plc Communication par satellite
US9674711B2 (en) 2013-11-06 2017-06-06 At&T Intellectual Property I, L.P. Surface-wave communications and methods thereof
US9685992B2 (en) 2014-10-03 2017-06-20 At&T Intellectual Property I, L.P. Circuit panel network and methods thereof
US9705610B2 (en) 2014-10-21 2017-07-11 At&T Intellectual Property I, L.P. Transmission device with impairment compensation and methods for use therewith
US9705561B2 (en) 2015-04-24 2017-07-11 At&T Intellectual Property I, L.P. Directional coupling device and methods for use therewith
US9729197B2 (en) 2015-10-01 2017-08-08 At&T Intellectual Property I, L.P. Method and apparatus for communicating network management traffic over a network
US9735833B2 (en) 2015-07-31 2017-08-15 At&T Intellectual Property I, L.P. Method and apparatus for communications management in a neighborhood network
US9742462B2 (en) 2014-12-04 2017-08-22 At&T Intellectual Property I, L.P. Transmission medium and communication interfaces and methods for use therewith
US9742521B2 (en) 2014-11-20 2017-08-22 At&T Intellectual Property I, L.P. Transmission device with mode division multiplexing and methods for use therewith
US9749053B2 (en) 2015-07-23 2017-08-29 At&T Intellectual Property I, L.P. Node device, repeater and methods for use therewith
US9748626B2 (en) 2015-05-14 2017-08-29 At&T Intellectual Property I, L.P. Plurality of cables having different cross-sectional shapes which are bundled together to form a transmission medium
US9749013B2 (en) 2015-03-17 2017-08-29 At&T Intellectual Property I, L.P. Method and apparatus for reducing attenuation of electromagnetic waves guided by a transmission medium
US9769128B2 (en) 2015-09-28 2017-09-19 At&T Intellectual Property I, L.P. Method and apparatus for encryption of communications over a network
US9769020B2 (en) 2014-10-21 2017-09-19 At&T Intellectual Property I, L.P. Method and apparatus for responding to events affecting communications in a communication network
US9768833B2 (en) 2014-09-15 2017-09-19 At&T Intellectual Property I, L.P. Method and apparatus for sensing a condition in a transmission medium of electromagnetic waves
US9780834B2 (en) 2014-10-21 2017-10-03 At&T Intellectual Property I, L.P. Method and apparatus for transmitting electromagnetic waves
US9787412B2 (en) 2015-06-25 2017-10-10 At&T Intellectual Property I, L.P. Methods and apparatus for inducing a fundamental wave mode on a transmission medium
US9793955B2 (en) 2015-04-24 2017-10-17 At&T Intellectual Property I, Lp Passive electrical coupling device and methods for use therewith
US9793954B2 (en) 2015-04-28 2017-10-17 At&T Intellectual Property I, L.P. Magnetic coupling device and methods for use therewith
US9800327B2 (en) 2014-11-20 2017-10-24 At&T Intellectual Property I, L.P. Apparatus for controlling operations of a communication device and methods thereof
WO2017165854A3 (fr) * 2016-03-24 2017-11-09 CyPhy Works, Inc. Système de reconnaissance et de communication aérienne persistante
US9820146B2 (en) 2015-06-12 2017-11-14 At&T Intellectual Property I, L.P. Method and apparatus for authentication and identity management of communicating devices
US9838078B2 (en) 2015-07-31 2017-12-05 At&T Intellectual Property I, L.P. Method and apparatus for exchanging communication signals
US9838896B1 (en) 2016-12-09 2017-12-05 At&T Intellectual Property I, L.P. Method and apparatus for assessing network coverage
US9847850B2 (en) 2014-10-14 2017-12-19 At&T Intellectual Property I, L.P. Method and apparatus for adjusting a mode of communication in a communication network
US9847566B2 (en) 2015-07-14 2017-12-19 At&T Intellectual Property I, L.P. Method and apparatus for adjusting a field of a signal to mitigate interference
US9853342B2 (en) 2015-07-14 2017-12-26 At&T Intellectual Property I, L.P. Dielectric transmission medium connector and methods for use therewith
US9860075B1 (en) 2016-08-26 2018-01-02 At&T Intellectual Property I, L.P. Method and communication node for broadband distribution
US9866309B2 (en) 2015-06-03 2018-01-09 At&T Intellectual Property I, Lp Host node device and methods for use therewith
US9865911B2 (en) 2015-06-25 2018-01-09 At&T Intellectual Property I, L.P. Waveguide system for slot radiating first electromagnetic waves that are combined into a non-fundamental wave mode second electromagnetic wave on a transmission medium
US9866276B2 (en) 2014-10-10 2018-01-09 At&T Intellectual Property I, L.P. Method and apparatus for arranging communication sessions in a communication system
US9871558B2 (en) 2014-10-21 2018-01-16 At&T Intellectual Property I, L.P. Guided-wave transmission device and methods for use therewith
US9871282B2 (en) 2015-05-14 2018-01-16 At&T Intellectual Property I, L.P. At least one transmission medium having a dielectric surface that is covered at least in part by a second dielectric
US9871283B2 (en) 2015-07-23 2018-01-16 At&T Intellectual Property I, Lp Transmission medium having a dielectric core comprised of plural members connected by a ball and socket configuration
US9876570B2 (en) 2015-02-20 2018-01-23 At&T Intellectual Property I, Lp Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9876264B2 (en) 2015-10-02 2018-01-23 At&T Intellectual Property I, Lp Communication system, guided wave switch and methods for use therewith
US9882257B2 (en) 2015-07-14 2018-01-30 At&T Intellectual Property I, L.P. Method and apparatus for launching a wave mode that mitigates interference
US9887447B2 (en) 2015-05-14 2018-02-06 At&T Intellectual Property I, L.P. Transmission medium having multiple cores and methods for use therewith
US9893795B1 (en) 2016-12-07 2018-02-13 At&T Intellectual Property I, Lp Method and repeater for broadband distribution
US9906269B2 (en) 2014-09-17 2018-02-27 At&T Intellectual Property I, L.P. Monitoring and mitigating conditions in a communication network
US9904535B2 (en) 2015-09-14 2018-02-27 At&T Intellectual Property I, L.P. Method and apparatus for distributing software
EP3288140A1 (fr) * 2016-08-22 2018-02-28 EE Limited Fourniture de puissance électrique
US9913139B2 (en) 2015-06-09 2018-03-06 At&T Intellectual Property I, L.P. Signal fingerprinting for authentication of communicating devices
US9912033B2 (en) 2014-10-21 2018-03-06 At&T Intellectual Property I, Lp Guided wave coupler, coupling module and methods for use therewith
US9912382B2 (en) 2015-06-03 2018-03-06 At&T Intellectual Property I, Lp Network termination and methods for use therewith
US9911020B1 (en) 2016-12-08 2018-03-06 At&T Intellectual Property I, L.P. Method and apparatus for tracking via a radio frequency identification device
US9912027B2 (en) 2015-07-23 2018-03-06 At&T Intellectual Property I, L.P. Method and apparatus for exchanging communication signals
US9917341B2 (en) 2015-05-27 2018-03-13 At&T Intellectual Property I, L.P. Apparatus and method for launching electromagnetic waves and for modifying radial dimensions of the propagating electromagnetic waves
US9927517B1 (en) 2016-12-06 2018-03-27 At&T Intellectual Property I, L.P. Apparatus and methods for sensing rainfall
US9929755B2 (en) 2015-07-14 2018-03-27 At&T Intellectual Property I, L.P. Method and apparatus for coupling an antenna to a device
US9948333B2 (en) 2015-07-23 2018-04-17 At&T Intellectual Property I, L.P. Method and apparatus for wireless communications to mitigate interference
US9954287B2 (en) 2014-11-20 2018-04-24 At&T Intellectual Property I, L.P. Apparatus for converting wireless signals and electromagnetic waves and methods thereof
US9954286B2 (en) 2014-10-21 2018-04-24 At&T Intellectual Property I, L.P. Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9967173B2 (en) 2015-07-31 2018-05-08 At&T Intellectual Property I, L.P. Method and apparatus for authentication and identity management of communicating devices
US9973940B1 (en) 2017-02-27 2018-05-15 At&T Intellectual Property I, L.P. Apparatus and methods for dynamic impedance matching of a guided wave launcher
US9973416B2 (en) 2014-10-02 2018-05-15 At&T Intellectual Property I, L.P. Method and apparatus that provides fault tolerance in a communication network
WO2018089859A1 (fr) * 2016-11-10 2018-05-17 CyPhy Works, Inc. Dispositifs et procédés pour des systèmes de communication cellulaire
US9999038B2 (en) 2013-05-31 2018-06-12 At&T Intellectual Property I, L.P. Remote distributed antenna system
US9998870B1 (en) 2016-12-08 2018-06-12 At&T Intellectual Property I, L.P. Method and apparatus for proximity sensing
US9997819B2 (en) 2015-06-09 2018-06-12 At&T Intellectual Property I, L.P. Transmission medium and method for facilitating propagation of electromagnetic waves via a core
US10009067B2 (en) 2014-12-04 2018-06-26 At&T Intellectual Property I, L.P. Method and apparatus for configuring a communication interface
WO2018118359A1 (fr) * 2016-12-22 2018-06-28 X Development Llc Approche intégrée pour utiliser l'optique en espace libre et une autre technologie de signal avec un cardan sur un aérostat attaché
US10020844B2 (en) 2016-12-06 2018-07-10 T&T Intellectual Property I, L.P. Method and apparatus for broadcast communication via guided waves
US10027397B2 (en) 2016-12-07 2018-07-17 At&T Intellectual Property I, L.P. Distributed antenna system and methods for use therewith
US10044409B2 (en) 2015-07-14 2018-08-07 At&T Intellectual Property I, L.P. Transmission medium and methods for use therewith
US10051630B2 (en) 2013-05-31 2018-08-14 At&T Intellectual Property I, L.P. Remote distributed antenna system
US10069185B2 (en) 2015-06-25 2018-09-04 At&T Intellectual Property I, L.P. Methods and apparatus for inducing a non-fundamental wave mode on a transmission medium
US10069535B2 (en) 2016-12-08 2018-09-04 At&T Intellectual Property I, L.P. Apparatus and methods for launching electromagnetic waves having a certain electric field structure
US10090606B2 (en) 2015-07-15 2018-10-02 At&T Intellectual Property I, L.P. Antenna system with dielectric array and methods for use therewith
US10090594B2 (en) 2016-11-23 2018-10-02 At&T Intellectual Property I, L.P. Antenna system having structural configurations for assembly
US10103422B2 (en) 2016-12-08 2018-10-16 At&T Intellectual Property I, L.P. Method and apparatus for mounting network devices
US10135145B2 (en) 2016-12-06 2018-11-20 At&T Intellectual Property I, L.P. Apparatus and methods for generating an electromagnetic wave along a transmission medium
US10139820B2 (en) 2016-12-07 2018-11-27 At&T Intellectual Property I, L.P. Method and apparatus for deploying equipment of a communication system
US10148016B2 (en) 2015-07-14 2018-12-04 At&T Intellectual Property I, L.P. Apparatus and methods for communicating utilizing an antenna array
US10168695B2 (en) 2016-12-07 2019-01-01 At&T Intellectual Property I, L.P. Method and apparatus for controlling an unmanned aircraft
US10178445B2 (en) 2016-11-23 2019-01-08 At&T Intellectual Property I, L.P. Methods, devices, and systems for load balancing between a plurality of waveguides
US10205655B2 (en) 2015-07-14 2019-02-12 At&T Intellectual Property I, L.P. Apparatus and methods for communicating utilizing an antenna array and multiple communication paths
US10225025B2 (en) 2016-11-03 2019-03-05 At&T Intellectual Property I, L.P. Method and apparatus for detecting a fault in a communication system
US10224634B2 (en) 2016-11-03 2019-03-05 At&T Intellectual Property I, L.P. Methods and apparatus for adjusting an operational characteristic of an antenna
US10243270B2 (en) 2016-12-07 2019-03-26 At&T Intellectual Property I, L.P. Beam adaptive multi-feed dielectric antenna system and methods for use therewith
WO2019067788A1 (fr) * 2017-09-27 2019-04-04 CyPhy Works, Inc. Système de commande et de communication aériennes permanentes
US10264586B2 (en) 2016-12-09 2019-04-16 At&T Mobility Ii Llc Cloud-based packet controller and methods for use therewith
US10291334B2 (en) 2016-11-03 2019-05-14 At&T Intellectual Property I, L.P. System for detecting a fault in a communication system
US10298293B2 (en) 2017-03-13 2019-05-21 At&T Intellectual Property I, L.P. Apparatus of communication utilizing wireless network devices
US10305190B2 (en) 2016-12-01 2019-05-28 At&T Intellectual Property I, L.P. Reflecting dielectric antenna system and methods for use therewith
US10312567B2 (en) 2016-10-26 2019-06-04 At&T Intellectual Property I, L.P. Launcher with planar strip antenna and methods for use therewith
US10326494B2 (en) 2016-12-06 2019-06-18 At&T Intellectual Property I, L.P. Apparatus for measurement de-embedding and methods for use therewith
US10326689B2 (en) 2016-12-08 2019-06-18 At&T Intellectual Property I, L.P. Method and system for providing alternative communication paths
CN109921845A (zh) * 2019-04-12 2019-06-21 清华大学 无线通信探测系统
US10340601B2 (en) 2016-11-23 2019-07-02 At&T Intellectual Property I, L.P. Multi-antenna system and methods for use therewith
US10340983B2 (en) 2016-12-09 2019-07-02 At&T Intellectual Property I, L.P. Method and apparatus for surveying remote sites via guided wave communications
US10340603B2 (en) 2016-11-23 2019-07-02 At&T Intellectual Property I, L.P. Antenna system having shielded structural configurations for assembly
US10355367B2 (en) 2015-10-16 2019-07-16 At&T Intellectual Property I, L.P. Antenna structure for exchanging wireless signals
US10361489B2 (en) 2016-12-01 2019-07-23 At&T Intellectual Property I, L.P. Dielectric dish antenna system and methods for use therewith
US10359749B2 (en) 2016-12-07 2019-07-23 At&T Intellectual Property I, L.P. Method and apparatus for utilities management via guided wave communication
US10382976B2 (en) 2016-12-06 2019-08-13 At&T Intellectual Property I, L.P. Method and apparatus for managing wireless communications based on communication paths and network device positions
US10389029B2 (en) 2016-12-07 2019-08-20 At&T Intellectual Property I, L.P. Multi-feed dielectric antenna system with core selection and methods for use therewith
US10389037B2 (en) 2016-12-08 2019-08-20 At&T Intellectual Property I, L.P. Apparatus and methods for selecting sections of an antenna array and use therewith
US10411356B2 (en) 2016-12-08 2019-09-10 At&T Intellectual Property I, L.P. Apparatus and methods for selectively targeting communication devices with an antenna array
US10439675B2 (en) 2016-12-06 2019-10-08 At&T Intellectual Property I, L.P. Method and apparatus for repeating guided wave communication signals
US10446936B2 (en) 2016-12-07 2019-10-15 At&T Intellectual Property I, L.P. Multi-feed dielectric antenna system and methods for use therewith
US10498044B2 (en) 2016-11-03 2019-12-03 At&T Intellectual Property I, L.P. Apparatus for configuring a surface of an antenna
US10507914B2 (en) 2013-03-15 2019-12-17 Flir Detection, Inc. Spooler for unmanned aerial vehicle system
US10530505B2 (en) 2016-12-08 2020-01-07 At&T Intellectual Property I, L.P. Apparatus and methods for launching electromagnetic waves along a transmission medium
US10535928B2 (en) 2016-11-23 2020-01-14 At&T Intellectual Property I, L.P. Antenna system and methods for use therewith
US10547348B2 (en) 2016-12-07 2020-01-28 At&T Intellectual Property I, L.P. Method and apparatus for switching transmission mediums in a communication system
US10601494B2 (en) 2016-12-08 2020-03-24 At&T Intellectual Property I, L.P. Dual-band communication device and method for use therewith
US10637149B2 (en) 2016-12-06 2020-04-28 At&T Intellectual Property I, L.P. Injection molded dielectric antenna and methods for use therewith
US10650940B2 (en) 2015-05-15 2020-05-12 At&T Intellectual Property I, L.P. Transmission medium having a conductive material and methods for use therewith
US10694379B2 (en) 2016-12-06 2020-06-23 At&T Intellectual Property I, L.P. Waveguide system with device-based authentication and methods for use therewith
US10727599B2 (en) 2016-12-06 2020-07-28 At&T Intellectual Property I, L.P. Launcher with slot antenna and methods for use therewith
US10755542B2 (en) 2016-12-06 2020-08-25 At&T Intellectual Property I, L.P. Method and apparatus for surveillance via guided wave communication
US10777873B2 (en) 2016-12-08 2020-09-15 At&T Intellectual Property I, L.P. Method and apparatus for mounting network devices
US10797781B2 (en) 2015-06-03 2020-10-06 At&T Intellectual Property I, L.P. Client node device and methods for use therewith
US10811767B2 (en) 2016-10-21 2020-10-20 At&T Intellectual Property I, L.P. System and dielectric antenna with convex dielectric radome
US10819035B2 (en) 2016-12-06 2020-10-27 At&T Intellectual Property I, L.P. Launcher with helical antenna and methods for use therewith
US10916969B2 (en) 2016-12-08 2021-02-09 At&T Intellectual Property I, L.P. Method and apparatus for providing power using an inductive coupling
US10926890B2 (en) 2017-11-29 2021-02-23 British Telecommunications Public Limited Company Delivery of electrical power to an unmanned aircraft
US10938108B2 (en) 2016-12-08 2021-03-02 At&T Intellectual Property I, L.P. Frequency selective multi-feed dielectric antenna system and methods for use therewith
US10993160B2 (en) 2017-09-05 2021-04-27 British Telecommunications Public Limited Company Cellular telecommunications network
US11071034B2 (en) 2017-08-15 2021-07-20 British Telecommunications Public Limited Company Moving cell backhaul coordination
US11184082B2 (en) 2016-09-29 2021-11-23 Ee Limited Cellular telephony
CN114465639A (zh) * 2022-04-08 2022-05-10 中国科学院空天信息创新研究院 一种链路切换系统及系留气球
US11417223B2 (en) 2020-01-19 2022-08-16 Flir Unmanned Aerial Systems Ulc Flight altitude estimation systems and methods
US11423790B2 (en) 2020-01-19 2022-08-23 Flir Unmanned Aerial Systems Ulc Tether management systems and methods
US11977395B2 (en) 2016-03-24 2024-05-07 Teledyne Flir Defense, Inc. Persistent aerial communication and control system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3742358A (en) * 1970-12-30 1973-06-26 R Cesaro Tethered airborne communications and information transfer system
US4842221A (en) * 1988-04-21 1989-06-27 Westinghouse Electric Corp. Lightning hardened tether cable and an aerostat tethered to a mooring system therewith
WO1997007609A2 (fr) * 1995-08-11 1997-02-27 Ramot University Authority For Applied Research & Industrial Development Ltd. Plate-forme a haute altitude pour systeme de telecommunications cellulaire
WO1998035506A2 (fr) * 1997-02-10 1998-08-13 Stanford Telecommunications, Inc. Passerelle de telecommunications a debit de donnees tres eleve pour telecommunications terre - espace - terre

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3742358A (en) * 1970-12-30 1973-06-26 R Cesaro Tethered airborne communications and information transfer system
US4842221A (en) * 1988-04-21 1989-06-27 Westinghouse Electric Corp. Lightning hardened tether cable and an aerostat tethered to a mooring system therewith
WO1997007609A2 (fr) * 1995-08-11 1997-02-27 Ramot University Authority For Applied Research & Industrial Development Ltd. Plate-forme a haute altitude pour systeme de telecommunications cellulaire
WO1998035506A2 (fr) * 1997-02-10 1998-08-13 Stanford Telecommunications, Inc. Passerelle de telecommunications a debit de donnees tres eleve pour telecommunications terre - espace - terre

Cited By (147)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2886491A1 (fr) * 2005-05-31 2006-12-01 Thales Sa Dispositif de transmission de signaux captes
RU2492574C2 (ru) * 2011-02-15 2013-09-10 Открытое акционерное общество Омское производственное объединение "Радиозавод им. А.С. Попова" (РЕЛЕРО) Способ установки ретранслятора при организации радиолинии связи
US10507914B2 (en) 2013-03-15 2019-12-17 Flir Detection, Inc. Spooler for unmanned aerial vehicle system
US11661187B2 (en) 2013-03-15 2023-05-30 Teledyne Flir Detection, Inc. Spooler for unmanned aerial vehicle system
US11180249B2 (en) 2013-03-15 2021-11-23 Flir Detection, Inc. Spooler for unmanned aerial vehicle system
US10051630B2 (en) 2013-05-31 2018-08-14 At&T Intellectual Property I, L.P. Remote distributed antenna system
US9999038B2 (en) 2013-05-31 2018-06-12 At&T Intellectual Property I, L.P. Remote distributed antenna system
US9674711B2 (en) 2013-11-06 2017-06-06 At&T Intellectual Property I, L.P. Surface-wave communications and methods thereof
US9768833B2 (en) 2014-09-15 2017-09-19 At&T Intellectual Property I, L.P. Method and apparatus for sensing a condition in a transmission medium of electromagnetic waves
US10063280B2 (en) 2014-09-17 2018-08-28 At&T Intellectual Property I, L.P. Monitoring and mitigating conditions in a communication network
US9906269B2 (en) 2014-09-17 2018-02-27 At&T Intellectual Property I, L.P. Monitoring and mitigating conditions in a communication network
US9973416B2 (en) 2014-10-02 2018-05-15 At&T Intellectual Property I, L.P. Method and apparatus that provides fault tolerance in a communication network
US9685992B2 (en) 2014-10-03 2017-06-20 At&T Intellectual Property I, L.P. Circuit panel network and methods thereof
US9866276B2 (en) 2014-10-10 2018-01-09 At&T Intellectual Property I, L.P. Method and apparatus for arranging communication sessions in a communication system
US9847850B2 (en) 2014-10-14 2017-12-19 At&T Intellectual Property I, L.P. Method and apparatus for adjusting a mode of communication in a communication network
US9912033B2 (en) 2014-10-21 2018-03-06 At&T Intellectual Property I, Lp Guided wave coupler, coupling module and methods for use therewith
US9960808B2 (en) 2014-10-21 2018-05-01 At&T Intellectual Property I, L.P. Guided-wave transmission device and methods for use therewith
US9769020B2 (en) 2014-10-21 2017-09-19 At&T Intellectual Property I, L.P. Method and apparatus for responding to events affecting communications in a communication network
US9871558B2 (en) 2014-10-21 2018-01-16 At&T Intellectual Property I, L.P. Guided-wave transmission device and methods for use therewith
US9780834B2 (en) 2014-10-21 2017-10-03 At&T Intellectual Property I, L.P. Method and apparatus for transmitting electromagnetic waves
US9954286B2 (en) 2014-10-21 2018-04-24 At&T Intellectual Property I, L.P. Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9876587B2 (en) 2014-10-21 2018-01-23 At&T Intellectual Property I, L.P. Transmission device with impairment compensation and methods for use therewith
US9705610B2 (en) 2014-10-21 2017-07-11 At&T Intellectual Property I, L.P. Transmission device with impairment compensation and methods for use therewith
US9800327B2 (en) 2014-11-20 2017-10-24 At&T Intellectual Property I, L.P. Apparatus for controlling operations of a communication device and methods thereof
US9749083B2 (en) 2014-11-20 2017-08-29 At&T Intellectual Property I, L.P. Transmission device with mode division multiplexing and methods for use therewith
US9954287B2 (en) 2014-11-20 2018-04-24 At&T Intellectual Property I, L.P. Apparatus for converting wireless signals and electromagnetic waves and methods thereof
US9742521B2 (en) 2014-11-20 2017-08-22 At&T Intellectual Property I, L.P. Transmission device with mode division multiplexing and methods for use therewith
EP3035071A3 (fr) * 2014-11-30 2016-10-19 Saab Medav Technologies GmbH Transmission de signal et dispositif de retenue pour des antennes embarquées d'un système de localisation rf
US9742462B2 (en) 2014-12-04 2017-08-22 At&T Intellectual Property I, L.P. Transmission medium and communication interfaces and methods for use therewith
US10009067B2 (en) 2014-12-04 2018-06-26 At&T Intellectual Property I, L.P. Method and apparatus for configuring a communication interface
US9876571B2 (en) 2015-02-20 2018-01-23 At&T Intellectual Property I, Lp Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9876570B2 (en) 2015-02-20 2018-01-23 At&T Intellectual Property I, Lp Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9749013B2 (en) 2015-03-17 2017-08-29 At&T Intellectual Property I, L.P. Method and apparatus for reducing attenuation of electromagnetic waves guided by a transmission medium
US9831912B2 (en) 2015-04-24 2017-11-28 At&T Intellectual Property I, Lp Directional coupling device and methods for use therewith
US9705561B2 (en) 2015-04-24 2017-07-11 At&T Intellectual Property I, L.P. Directional coupling device and methods for use therewith
US9793955B2 (en) 2015-04-24 2017-10-17 At&T Intellectual Property I, Lp Passive electrical coupling device and methods for use therewith
US9793954B2 (en) 2015-04-28 2017-10-17 At&T Intellectual Property I, L.P. Magnetic coupling device and methods for use therewith
US9748626B2 (en) 2015-05-14 2017-08-29 At&T Intellectual Property I, L.P. Plurality of cables having different cross-sectional shapes which are bundled together to form a transmission medium
US9887447B2 (en) 2015-05-14 2018-02-06 At&T Intellectual Property I, L.P. Transmission medium having multiple cores and methods for use therewith
US9871282B2 (en) 2015-05-14 2018-01-16 At&T Intellectual Property I, L.P. At least one transmission medium having a dielectric surface that is covered at least in part by a second dielectric
US10650940B2 (en) 2015-05-15 2020-05-12 At&T Intellectual Property I, L.P. Transmission medium having a conductive material and methods for use therewith
US9917341B2 (en) 2015-05-27 2018-03-13 At&T Intellectual Property I, L.P. Apparatus and method for launching electromagnetic waves and for modifying radial dimensions of the propagating electromagnetic waves
US10797781B2 (en) 2015-06-03 2020-10-06 At&T Intellectual Property I, L.P. Client node device and methods for use therewith
US10812174B2 (en) 2015-06-03 2020-10-20 At&T Intellectual Property I, L.P. Client node device and methods for use therewith
US9935703B2 (en) 2015-06-03 2018-04-03 At&T Intellectual Property I, L.P. Host node device and methods for use therewith
US9866309B2 (en) 2015-06-03 2018-01-09 At&T Intellectual Property I, Lp Host node device and methods for use therewith
US9967002B2 (en) 2015-06-03 2018-05-08 At&T Intellectual I, Lp Network termination and methods for use therewith
US10050697B2 (en) 2015-06-03 2018-08-14 At&T Intellectual Property I, L.P. Host node device and methods for use therewith
US9912381B2 (en) 2015-06-03 2018-03-06 At&T Intellectual Property I, Lp Network termination and methods for use therewith
US9912382B2 (en) 2015-06-03 2018-03-06 At&T Intellectual Property I, Lp Network termination and methods for use therewith
US9997819B2 (en) 2015-06-09 2018-06-12 At&T Intellectual Property I, L.P. Transmission medium and method for facilitating propagation of electromagnetic waves via a core
US9913139B2 (en) 2015-06-09 2018-03-06 At&T Intellectual Property I, L.P. Signal fingerprinting for authentication of communicating devices
US9820146B2 (en) 2015-06-12 2017-11-14 At&T Intellectual Property I, L.P. Method and apparatus for authentication and identity management of communicating devices
US10069185B2 (en) 2015-06-25 2018-09-04 At&T Intellectual Property I, L.P. Methods and apparatus for inducing a non-fundamental wave mode on a transmission medium
US9787412B2 (en) 2015-06-25 2017-10-10 At&T Intellectual Property I, L.P. Methods and apparatus for inducing a fundamental wave mode on a transmission medium
US9865911B2 (en) 2015-06-25 2018-01-09 At&T Intellectual Property I, L.P. Waveguide system for slot radiating first electromagnetic waves that are combined into a non-fundamental wave mode second electromagnetic wave on a transmission medium
US10148016B2 (en) 2015-07-14 2018-12-04 At&T Intellectual Property I, L.P. Apparatus and methods for communicating utilizing an antenna array
US10205655B2 (en) 2015-07-14 2019-02-12 At&T Intellectual Property I, L.P. Apparatus and methods for communicating utilizing an antenna array and multiple communication paths
US9929755B2 (en) 2015-07-14 2018-03-27 At&T Intellectual Property I, L.P. Method and apparatus for coupling an antenna to a device
US9882257B2 (en) 2015-07-14 2018-01-30 At&T Intellectual Property I, L.P. Method and apparatus for launching a wave mode that mitigates interference
US10044409B2 (en) 2015-07-14 2018-08-07 At&T Intellectual Property I, L.P. Transmission medium and methods for use therewith
US9847566B2 (en) 2015-07-14 2017-12-19 At&T Intellectual Property I, L.P. Method and apparatus for adjusting a field of a signal to mitigate interference
US9853342B2 (en) 2015-07-14 2017-12-26 At&T Intellectual Property I, L.P. Dielectric transmission medium connector and methods for use therewith
US10090606B2 (en) 2015-07-15 2018-10-02 At&T Intellectual Property I, L.P. Antenna system with dielectric array and methods for use therewith
US9871283B2 (en) 2015-07-23 2018-01-16 At&T Intellectual Property I, Lp Transmission medium having a dielectric core comprised of plural members connected by a ball and socket configuration
US9749053B2 (en) 2015-07-23 2017-08-29 At&T Intellectual Property I, L.P. Node device, repeater and methods for use therewith
US9912027B2 (en) 2015-07-23 2018-03-06 At&T Intellectual Property I, L.P. Method and apparatus for exchanging communication signals
US9806818B2 (en) 2015-07-23 2017-10-31 At&T Intellectual Property I, Lp Node device, repeater and methods for use therewith
US9948333B2 (en) 2015-07-23 2018-04-17 At&T Intellectual Property I, L.P. Method and apparatus for wireless communications to mitigate interference
WO2017017100A1 (fr) * 2015-07-27 2017-02-02 Avanti Communications Group Plc Communication par satellite
US9838078B2 (en) 2015-07-31 2017-12-05 At&T Intellectual Property I, L.P. Method and apparatus for exchanging communication signals
US9967173B2 (en) 2015-07-31 2018-05-08 At&T Intellectual Property I, L.P. Method and apparatus for authentication and identity management of communicating devices
US9735833B2 (en) 2015-07-31 2017-08-15 At&T Intellectual Property I, L.P. Method and apparatus for communications management in a neighborhood network
US9904535B2 (en) 2015-09-14 2018-02-27 At&T Intellectual Property I, L.P. Method and apparatus for distributing software
US9769128B2 (en) 2015-09-28 2017-09-19 At&T Intellectual Property I, L.P. Method and apparatus for encryption of communications over a network
US9729197B2 (en) 2015-10-01 2017-08-08 At&T Intellectual Property I, L.P. Method and apparatus for communicating network management traffic over a network
US9876264B2 (en) 2015-10-02 2018-01-23 At&T Intellectual Property I, Lp Communication system, guided wave switch and methods for use therewith
US10355367B2 (en) 2015-10-16 2019-07-16 At&T Intellectual Property I, L.P. Antenna structure for exchanging wireless signals
US11174021B2 (en) 2016-03-24 2021-11-16 Flir Detection, Inc. Persistent aerial reconnaissance and communication system
US11977395B2 (en) 2016-03-24 2024-05-07 Teledyne Flir Defense, Inc. Persistent aerial communication and control system
WO2017165854A3 (fr) * 2016-03-24 2017-11-09 CyPhy Works, Inc. Système de reconnaissance et de communication aérienne persistante
US11563329B2 (en) 2016-08-22 2023-01-24 Ee Limited Delivery of electrical power
EP3288140A1 (fr) * 2016-08-22 2018-02-28 EE Limited Fourniture de puissance électrique
WO2018036870A1 (fr) * 2016-08-22 2018-03-01 Ee Limited Fourniture d'énergie électrique
US9860075B1 (en) 2016-08-26 2018-01-02 At&T Intellectual Property I, L.P. Method and communication node for broadband distribution
US11184082B2 (en) 2016-09-29 2021-11-23 Ee Limited Cellular telephony
US10811767B2 (en) 2016-10-21 2020-10-20 At&T Intellectual Property I, L.P. System and dielectric antenna with convex dielectric radome
US10312567B2 (en) 2016-10-26 2019-06-04 At&T Intellectual Property I, L.P. Launcher with planar strip antenna and methods for use therewith
US10224634B2 (en) 2016-11-03 2019-03-05 At&T Intellectual Property I, L.P. Methods and apparatus for adjusting an operational characteristic of an antenna
US10291334B2 (en) 2016-11-03 2019-05-14 At&T Intellectual Property I, L.P. System for detecting a fault in a communication system
US10498044B2 (en) 2016-11-03 2019-12-03 At&T Intellectual Property I, L.P. Apparatus for configuring a surface of an antenna
US10225025B2 (en) 2016-11-03 2019-03-05 At&T Intellectual Property I, L.P. Method and apparatus for detecting a fault in a communication system
WO2018089859A1 (fr) * 2016-11-10 2018-05-17 CyPhy Works, Inc. Dispositifs et procédés pour des systèmes de communication cellulaire
US10178445B2 (en) 2016-11-23 2019-01-08 At&T Intellectual Property I, L.P. Methods, devices, and systems for load balancing between a plurality of waveguides
US10535928B2 (en) 2016-11-23 2020-01-14 At&T Intellectual Property I, L.P. Antenna system and methods for use therewith
US10340603B2 (en) 2016-11-23 2019-07-02 At&T Intellectual Property I, L.P. Antenna system having shielded structural configurations for assembly
US10090594B2 (en) 2016-11-23 2018-10-02 At&T Intellectual Property I, L.P. Antenna system having structural configurations for assembly
US10340601B2 (en) 2016-11-23 2019-07-02 At&T Intellectual Property I, L.P. Multi-antenna system and methods for use therewith
US10361489B2 (en) 2016-12-01 2019-07-23 At&T Intellectual Property I, L.P. Dielectric dish antenna system and methods for use therewith
US10305190B2 (en) 2016-12-01 2019-05-28 At&T Intellectual Property I, L.P. Reflecting dielectric antenna system and methods for use therewith
US10637149B2 (en) 2016-12-06 2020-04-28 At&T Intellectual Property I, L.P. Injection molded dielectric antenna and methods for use therewith
US10694379B2 (en) 2016-12-06 2020-06-23 At&T Intellectual Property I, L.P. Waveguide system with device-based authentication and methods for use therewith
US10135145B2 (en) 2016-12-06 2018-11-20 At&T Intellectual Property I, L.P. Apparatus and methods for generating an electromagnetic wave along a transmission medium
US9927517B1 (en) 2016-12-06 2018-03-27 At&T Intellectual Property I, L.P. Apparatus and methods for sensing rainfall
US10819035B2 (en) 2016-12-06 2020-10-27 At&T Intellectual Property I, L.P. Launcher with helical antenna and methods for use therewith
US10020844B2 (en) 2016-12-06 2018-07-10 T&T Intellectual Property I, L.P. Method and apparatus for broadcast communication via guided waves
US10326494B2 (en) 2016-12-06 2019-06-18 At&T Intellectual Property I, L.P. Apparatus for measurement de-embedding and methods for use therewith
US10755542B2 (en) 2016-12-06 2020-08-25 At&T Intellectual Property I, L.P. Method and apparatus for surveillance via guided wave communication
US10439675B2 (en) 2016-12-06 2019-10-08 At&T Intellectual Property I, L.P. Method and apparatus for repeating guided wave communication signals
US10727599B2 (en) 2016-12-06 2020-07-28 At&T Intellectual Property I, L.P. Launcher with slot antenna and methods for use therewith
US10382976B2 (en) 2016-12-06 2019-08-13 At&T Intellectual Property I, L.P. Method and apparatus for managing wireless communications based on communication paths and network device positions
US10389029B2 (en) 2016-12-07 2019-08-20 At&T Intellectual Property I, L.P. Multi-feed dielectric antenna system with core selection and methods for use therewith
US10359749B2 (en) 2016-12-07 2019-07-23 At&T Intellectual Property I, L.P. Method and apparatus for utilities management via guided wave communication
US10547348B2 (en) 2016-12-07 2020-01-28 At&T Intellectual Property I, L.P. Method and apparatus for switching transmission mediums in a communication system
US10243270B2 (en) 2016-12-07 2019-03-26 At&T Intellectual Property I, L.P. Beam adaptive multi-feed dielectric antenna system and methods for use therewith
US10446936B2 (en) 2016-12-07 2019-10-15 At&T Intellectual Property I, L.P. Multi-feed dielectric antenna system and methods for use therewith
US10168695B2 (en) 2016-12-07 2019-01-01 At&T Intellectual Property I, L.P. Method and apparatus for controlling an unmanned aircraft
US10139820B2 (en) 2016-12-07 2018-11-27 At&T Intellectual Property I, L.P. Method and apparatus for deploying equipment of a communication system
US10027397B2 (en) 2016-12-07 2018-07-17 At&T Intellectual Property I, L.P. Distributed antenna system and methods for use therewith
US9893795B1 (en) 2016-12-07 2018-02-13 At&T Intellectual Property I, Lp Method and repeater for broadband distribution
US10069535B2 (en) 2016-12-08 2018-09-04 At&T Intellectual Property I, L.P. Apparatus and methods for launching electromagnetic waves having a certain electric field structure
US10777873B2 (en) 2016-12-08 2020-09-15 At&T Intellectual Property I, L.P. Method and apparatus for mounting network devices
US10103422B2 (en) 2016-12-08 2018-10-16 At&T Intellectual Property I, L.P. Method and apparatus for mounting network devices
US10530505B2 (en) 2016-12-08 2020-01-07 At&T Intellectual Property I, L.P. Apparatus and methods for launching electromagnetic waves along a transmission medium
US10411356B2 (en) 2016-12-08 2019-09-10 At&T Intellectual Property I, L.P. Apparatus and methods for selectively targeting communication devices with an antenna array
US10389037B2 (en) 2016-12-08 2019-08-20 At&T Intellectual Property I, L.P. Apparatus and methods for selecting sections of an antenna array and use therewith
US9911020B1 (en) 2016-12-08 2018-03-06 At&T Intellectual Property I, L.P. Method and apparatus for tracking via a radio frequency identification device
US9998870B1 (en) 2016-12-08 2018-06-12 At&T Intellectual Property I, L.P. Method and apparatus for proximity sensing
US10938108B2 (en) 2016-12-08 2021-03-02 At&T Intellectual Property I, L.P. Frequency selective multi-feed dielectric antenna system and methods for use therewith
US10601494B2 (en) 2016-12-08 2020-03-24 At&T Intellectual Property I, L.P. Dual-band communication device and method for use therewith
US10916969B2 (en) 2016-12-08 2021-02-09 At&T Intellectual Property I, L.P. Method and apparatus for providing power using an inductive coupling
US10326689B2 (en) 2016-12-08 2019-06-18 At&T Intellectual Property I, L.P. Method and system for providing alternative communication paths
US10340983B2 (en) 2016-12-09 2019-07-02 At&T Intellectual Property I, L.P. Method and apparatus for surveying remote sites via guided wave communications
US10264586B2 (en) 2016-12-09 2019-04-16 At&T Mobility Ii Llc Cloud-based packet controller and methods for use therewith
US9838896B1 (en) 2016-12-09 2017-12-05 At&T Intellectual Property I, L.P. Method and apparatus for assessing network coverage
WO2018118359A1 (fr) * 2016-12-22 2018-06-28 X Development Llc Approche intégrée pour utiliser l'optique en espace libre et une autre technologie de signal avec un cardan sur un aérostat attaché
US9973940B1 (en) 2017-02-27 2018-05-15 At&T Intellectual Property I, L.P. Apparatus and methods for dynamic impedance matching of a guided wave launcher
US10298293B2 (en) 2017-03-13 2019-05-21 At&T Intellectual Property I, L.P. Apparatus of communication utilizing wireless network devices
US11071034B2 (en) 2017-08-15 2021-07-20 British Telecommunications Public Limited Company Moving cell backhaul coordination
US10993160B2 (en) 2017-09-05 2021-04-27 British Telecommunications Public Limited Company Cellular telecommunications network
WO2019067788A1 (fr) * 2017-09-27 2019-04-04 CyPhy Works, Inc. Système de commande et de communication aériennes permanentes
US10926890B2 (en) 2017-11-29 2021-02-23 British Telecommunications Public Limited Company Delivery of electrical power to an unmanned aircraft
CN109921845A (zh) * 2019-04-12 2019-06-21 清华大学 无线通信探测系统
US11417223B2 (en) 2020-01-19 2022-08-16 Flir Unmanned Aerial Systems Ulc Flight altitude estimation systems and methods
US11423790B2 (en) 2020-01-19 2022-08-23 Flir Unmanned Aerial Systems Ulc Tether management systems and methods
CN114465639A (zh) * 2022-04-08 2022-05-10 中国科学院空天信息创新研究院 一种链路切换系统及系留气球
CN114465639B (zh) * 2022-04-08 2022-08-02 中国科学院空天信息创新研究院 一种链路切换系统及系留气球

Also Published As

Publication number Publication date
GB0102639D0 (en) 2001-03-21
EP1358723A1 (fr) 2003-11-05

Similar Documents

Publication Publication Date Title
WO2002061971A1 (fr) Systeme de communication a l'aide d'un aerostat captif au-dessus de la surface de la terre et lie a une station de base par une fibre optique
KR100878646B1 (ko) 통신 시스템
Djuknic et al. Establishing wireless communications services via high-altitude aeronautical platforms: a concept whose time has come?
US9973260B2 (en) Global communication network
Karapantazis et al. Broadband communications via high-altitude platforms: A survey
US9871577B2 (en) Global communication network
Widiawan et al. High altitude platform station (HAPS): A review of new infrastructure development for future wireless communications
CA3116223A1 (fr) Systemes et procedes pour plateforme hybride radio/optique haute altitude
CN107431519B (zh) 一种用于改进数据传送的过程和装置
KR20010031643A (ko) 항공 스위칭 노드를 사용하는 무선 통신
JPH08213945A (ja) 衛星通信システム
WO1999013598A1 (fr) Telecommunication au moyen d'une plate-forme atmospherique
Hase et al. A novel broadband all-wireless access network using stratospheric platforms
WO1998035506A2 (fr) Passerelle de telecommunications a debit de donnees tres eleve pour telecommunications terre - espace - terre
Khalifa et al. High altitude platform for wireless communications and other services
WO2001059961A9 (fr) Systeme et procede de telecommunications optiques en altitude
Miura et al. Experiment of telecom/broadcasting mission using a high-altitude solar-powered aerial vehicle Pathfinder Plus
Hase et al. Wireless communication systems using stratospheric platforms
Labbé LEO Satellite Constellations: An Opportunity to Improve Terrestrial Communications in the Canadian Arctic
Thornton et al. A WiMAX payload for high altitude platform experimental trials
Wells et al. COMMStellation-A Low Latency Satellite Constellation for Broadband Communications
Kassa et al. A most promising HAPs technology for next generation wireless communication systems
Ilcev et al. Development of stratospheric communication platforms (SCP) for rural applications
Freitag et al. Global EHF satellite network for delivering fibre optic capacity world wide
Losquadro et al. A Ka/EHF band geostationary satellite system to provide multimedia services to terrestrial and aeronautical users

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PH PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2001978609

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 2001978609

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

WWW Wipo information: withdrawn in national office

Ref document number: 2001978609

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: JP